Nursing Elites

1. Which of the following valves prevents backflow of blood from the right ventricle into the right atrium of the heart?

• A. Aortic
• B. Tricuspid valve
• C. Pulmonic
• D. Mitral valve

Correct answer: B

Rationale: The correct answer is the tricuspid valve. The tricuspid valve is located between the right atrium and the right ventricle of the heart. Its main function is to prevent the backflow of blood from the right ventricle into the right atrium during the heart's pumping cycle. Choice A, the aortic valve, is responsible for preventing backflow from the aorta into the left ventricle. Choice C, the pulmonic valve, prevents backflow from the pulmonary artery into the right ventricle. Choice D, the mitral valve, prevents backflow from the left ventricle into the left atrium.

2. Cells do not aggregate into organelles based on similar functions.

• A. TRUE
• B. FALSE
• C. Not Sure
• D. None of the above

Correct answer: B

Rationale: The statement is false. Cells with similar functions do not aggregate into organelles. Organelles are specialized structures within cells that perform specific functions, such as the nucleus, mitochondria, and endoplasmic reticulum. Cells themselves are the basic structural and functional units of organisms, and organelles are located within cells to carry out various tasks. Therefore, cells do not aggregate into organelles, but organelles are found within cells to support their functions. Choices A, C, and D are incorrect as cells do not form organelles by aggregating based on similar functions.

3. The maintenance of a steady body temperature in the face of fluctuating environmental conditions illustrates homeostasis.

• A. TRUE
• B. FALSE
• C. Not Sure
• D. None of the above

Correct answer: A

Rationale: The correct answer is True. Homeostasis is the body's ability to maintain a stable internal environment despite external changes. In this case, the maintenance of a steady body temperature despite fluctuations in environmental conditions is a clear example of homeostasis. The body regulates temperature through processes like sweating when it's hot and shivering when it's cold. Choices B, C, and D are incorrect because the statement provided does indeed illustrate the concept of homeostasis, making them inaccurate.

4. Which of the following is not an example of a homeostatic mechanism in the human body?

• A. Shivering when the body temperature falls below normal.
• B. Increasing heart rate and force of contraction when blood pressure falls.
• C. Retaining fluid excessively.
• D. Secreting insulin after a meal to return blood sugar concentration toward normal.

Correct answer: C

Rationale: The correct answer is C. Homeostatic mechanisms aim to maintain internal stability within the body. Choices A, B, and D all represent examples of homeostatic mechanisms. Shivering helps generate heat to raise body temperature back to normal levels. Increasing heart rate and force of contraction work to restore blood pressure. Insulin secretion after a meal helps regulate blood sugar levels. On the other hand, retaining fluid excessively can lead to fluid imbalance rather than maintaining internal stability, making it the incorrect choice.

5. Specialized cell types organized in a way that provides a specific function form

• A. tissues, which build organs.
• B. organs, which build tissues.
• C. organ systems, which build tissues.
• D. atoms, which comprise tissues.

Correct answer: A

Rationale: The correct answer is 'tissues, which build organs.' Specialized cell types organize to form tissues, which in turn build organs. Tissues are groups of cells that work together to perform a specific function. Option B is incorrect because organs are composed of tissues, not the other way around. Option C is incorrect as organ systems consist of multiple organs working together, not building tissues. Option D is incorrect as atoms are the basic building blocks of matter and are not directly involved in forming tissues.

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